Tuesday, September 11, 2012

In any operating system, it is possible to create jobs that you want to reoccur. This process, known as job scheduling, is usually done based on user-defined jobs. For Red Hat or any other Linux, this process is handled by the cron service or a daemon called crond, which can be used to schedule tasks also called jobs. By default, Red Hat comes with a set of predefined jobs that occur on the system(hourly, daily, weekly, monthly, and with arbitrary periodicity. As an administrator, however, you can define your own jobs and allow users to create them as well.

The importance of the job scheduling is that some times, we need to run some scripts, which check the free space in mount point. In this case, it will check the free space on hourly basis and send mail to respective user you want. In this case, we can't run script manually on hourly basis. To avoid this manual work, we are doing job scheduling by crontab.